Ni4-thiacalix[4]arene sandwiched Mo8 polyoxometalate bimetallic nanoclusters for electrocatalytic glucose oxidation

Available online two new Ni8Mo8 bimetallic coordination clusters, [Ni4(TC4A)]2[(Mo5VMo3VIO24)(PO4)] (+Solvent) (Ni8PMo8, H4TC4A= p-tert-butylthiacalix[4]arene) and [Ni4(TC4A)]2[(Mo5VMo3VIO24)(OH)(CO3)] (+Solvent) (Ni8Mo8), were synthesized by solvothermal method and structurally characterized by single-crystal X-ray diffraction, powder X-ray diffraction, FT-IR spectroscopy, and TGA experiments, respectively. The usage of H3PMo12O40 as source for Ni8PMo8 resulted a sandwich like structure built from two Ni4-thiacalix[4]arene units and a Mo8 polyoxometalate with inner spaces of PO43−. Ni8Mo8 with the similar structure to that of Ni8PMo8 is from H2MoO4 starting reagent with OH− and CO32− anions encapsulated in the center. The two clusters can be directly loaded on carbon paper and utilized as working electrodes which showed distinguishable performances for glucose detection and oxidation. This work provides a better understanding of the structure–property relationships in using substituted polyoxometalates for electrochemical applications and is helpful for building calixarene-based or polyoxometalate-based functional materials.